• Proceedings of the KSR Conference
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• 2006.11b
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• pp.779-785
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• 2006

This paper introduces a result of internal signal modeling for a defect diagnosis of the UM-71C track circuit using on HSL. Actually, We fixed a sample area within operating section on HSL and performed the simulations for short circuit current that is reflected characteristic impedance and propagation factor. We compared the measuring data with the result of the simulation. These modeling can be used as the basic data for secure of the safety. Also, It need to make a criteria of analysis for the maintenance through comparison simulation data and inspection data.

• Archives of Craniofacial Surgery
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• v.10 no.2
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• pp.71-75
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• 2009

Purpose: Recently, orbital wall fracture is common injuries in the face. Facial CT is essential for the accurate diagnosis and appropriate treatment to reconstruct of the orbital wall. The objective of this study was to report the method for accurate measurement of area and shape of the bony defect in the blow-out fractures using facial CT in prior to surgery. Methods: The authors experienced 46 cases of orbital wall fractures and examined for diplopia, sensory disturbance in the area of distribution of the infraorbital nerve, and enophthalmos in the preoperation and followed 1 months after surgery, from August 2007 to May 2008. Bony defect was predicted by measuring continuous defect size from 3 mm interval facial CT. Copying from the defect model (template), we reconstructed orbital wall with resorbable sheet (Inion $CPS^{(R)}$ Inion Oy, Tampere, Finland). Results: One months after surgery using this method, 26 (100%) of the 26 patients improved in the diplopia and sensory disturbance in the area of distribution of the infraorbital nerve. Also 8 (72.7%) of the 11 patients had enophthalmos took favorable turn. Conclusion: This accurate and time-saving method is practicable for determining the location, shape and size of the bony defect. Using this method, we can reconstruct orbital wall fracture fastly and precisely.

• The Journal of the Korean bone and joint tumor society
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• v.5 no.3
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• pp.155-161
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• 1999

This study was performed to document the morphologic relationships between non-ossifying fibroma (NOF) and fibrous cortical defect (FCD), as well as to determine any new diagnostic clues. Eighteen patients with 21 NOFs and 14 patients with 15 FCDs found incidentally on radiography were included. The authors prospectively performed CT, MRI, or both on all subjects. The study included size, location, sclerotic property and contour of the periphery, as well as calcification of the matrix of the lesions and the distance from the lesion to the growth plate. The morphologic characteristics were thoroughly reviewed focusing on the presence of the cortical tract in the lesions. The size of the lesion and the distance from the growth plate were not correlated with the patient' age. The presence of the cortical tract was noted in 18(85.7%) out of 21 NOFs, and 10(66.7%) out of 15 FCDs. The presence of the cortical tract was correlated with the longitudinal length of the lesion and the distance from the growth plate. The presence of the cortical tract may be one of the important characteristics in NOF and FCD, and if the diagnosis of bony lesions is obscure by radiologic finding, its exsitence may be a good indicator of diagnosis for NOF or FCD.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1656-1664
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• 2007

This paper introduces a study of improvement for a defect diagnosis of the UM71C track circuit using on HSL. The track circuit on HSL has long operation section. Therefore, when the worker maintain, many times and efforts are spent. So, periodically, we have operated a inspection car. However, we don't know exactly the state changed of the inspection data when track circuit has defect. Actually, We fixed a sample area within operation section on HSL and performed the simulations for short circuit current that is reflected characteristic impedance and propagation factor. We compared the measuring data with the result of the simulation. Using verified simulation program, we estimated inspection data as the malfunction number and the change of capacity of compensation capacitor. These study need to secure of the safety as the train operation. Also, It needs to make a criteria of analysis for the maintenance through comparison simulation data and inspection data.

• Journal of Genetic Medicine
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• v.17 no.1
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• pp.16-20
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• 2020

Purpose: Duodenal atresia (DA) and atrioventricular septal defect (AVSD) are well known ultrasonographic findings associated with Down syndrome. The risk of Down syndrome in fetuses with these anomalies has been reported as 30% to 40%. However, on the basis of our clinical experience, the risk of Down syndrome of DA may be lower in Korean population. To clarify this issue, we compared the risk of Down syndrome between cases with DA and AVSD. Materials and Methods: The study population consisted of neonates who were confirmed as DA or AVSD by postnatal diagnosis. Postnatal diagnosis was made by surgery, postnatal echocardiography, or autopsy. Medical record was reviewed retrospectively. Results: A total of 213 neonates with DA or AVSD were included: 67 cases with DA and 146 cases with AVSD. The risk of Down syndrome was 4.5% (3/67) in DA vs. 29.5% (43/146) in AVSD. When confining analysis to those whose karyotyping were not performed during antenatal period, the risk of Down syndrome were 7.9% (3/38) in DA and 35.4% (35/99) in AVSD. Conclusion: The risk of Down syndrome in cases with DA was much lower in Korean population than previously reported risk in the literature. The significance of some antenatal sonographic markers for Down syndrome may be different according to ethnicity.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.4
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• pp.323-330
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• 2008

High cycle bending fatigue of socket welded small bore pipe was characterized, and also the fatigue crack initiation of small bore pipe was monitored in situ by the acoustic emission (AE) technique. The STS 316L stainless steel specimens were prepared by gas tungsten arc welding (GTAW) process having the artificial defect (i.e., lack of penetration) and defect free at the root. The fatigue failure was occurred at the loc for high stress and root for relatively low stress. The crack initiation cycles ($N_i$) was defined to the abrupt increase in AE counts during the fatigue test, and then the cracks were observed by the radiographic test and electron microscope before and after the fatigue crack initiation cycles. The socket welded pipe damaged by bending fatigue was studied regarding the welding defect, failure mode, and crack initiation cycles for the diagnosis and monitoring.

• Korean Journal of Radiology
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• v.22 no.3
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• pp.395-404
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• 2021

Objective: To compare the utility of computed tomography perfusion (CTP) and three different 4-point scoring systems in computed tomography angiography (CTA) in confirming brain death (BD) in patients with and without skull defects. Materials and Methods: Ninety-two patients clinically diagnosed as BD using CTA and/or CTP for confirmation were retrospectively reviewed. For the final analysis, 86 patients were included in this study. Images were re-evaluated by three radiologists according to the 4-point scoring systems that consider the vessel opacification on 1) the venous phase for both M4 segments of the middle cerebral arteries (MCAs-M4) and internal cerebral veins (ICVs) (A60-V60), 2) the arterial phase for the MCA-M4 and venous phase for the ICVs (A20-V60), 3) the venous phase for the ICVs and superior petrosal veins (ICV-SPV). The CTP images were independently reviewed. The presence of an open skull defect and stasis filling was noted. Results: Sensitivities of the ICV-SPV, A20-V60, A60-V60 scoring systems, and CTP in the diagnosis of BD were 89.5%, 82.6%, 67.4%, and 93.3%, respectively. The sensitivity of A20-V60 scoring was higher than that of A60-V60 in BD patients (p < 0.001). CTP was found to be the most sensitive method (86.5%) in patients with open skull defect (p = 0.019). Interobserver agreement was excellent in the diagnosis of BD, in assessing A20-V60, A60-V60, ICV-SPV, CTP, and good in stasis filling (κ: 0.84, 0.83, 0.83, 0.83, and 0.67, respectively). Conclusion: The sensitivity of CTA confirming brain death differs between various proposed 4-point scoring systems. Although the ICV-SPV is the most sensitive, evaluation of the SPV is challenging. Adding CTP to the routine BD CTA protocol, especially in cases with open skull defect, could increase sensitivity as a useful adjunct.

• Imaging Science in Dentistry
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• v.37 no.4
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• pp.221-223
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• 2007

The radiographic diagnosis of typical Stafne bone cavity could be done easily with cyst-like round or oval radiolucency near the angle of the mandible, under mandibular canal with or without involving mandibular base, and no symptoms. However there are some atypical cases suggesting possible variations of this entity. We report a quite unusual case, where Stafne bone cavity was lastly included in the differential diagnosis list. Histological examination of salivary gland tissues confirmed the final diagnosis.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1860-1862
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• 2004

It is widely known that the ultra high frequency (UHF) method that detects the electromagnetic wave of the PD pulses in the gas insulated space is one of the most competitive methods for its high sensitivity. From the above point of view, this paper describes the characteristics of GIS PD signals measured with ultra wide band (UWB) GIS PD detecting system in which PD signals are detected into the dual UHF band. The UWB PD detection system consists of the UWB UHF coupler, the UWB low noise amplifier (LNA) and the oscilloscope. The dual bands for PD signals are 0.5-2GHz(full band) and 1-2GHz(high band). As results, it was found that the partial discharges of each defect have their own characteristic pattern and the ratio of High band to Full band increases with gas pressure.

• Journal of KSNVE
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• v.10 no.2
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• pp.331-337
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• 2000

The necessity of diagnosis of the rotating machinery which is widely used in the industry is increasing. Many research has been conducted to manipulate field vibration signal data for diagnosing the fault of designated machinery. As the pattern recognition tool of that signal, neural network which use usually back-propagation algorithm was used in the diagnosis of rotating machinery. In this paper, self-organizing feature map(SOFM) which is unsupervised learning algorithm is used in the abnormal defect diagnosis of rotating machinery and then learning vector quantization(LVQ) which is supervised learning algorithm is used to improve the quality of the classifier decision regions.